Thermometric alarm switch



Jan. 25, 1949.

J. o. LEE

THERMOMETRIC ALARM SWI TCH Filed Sept. e, 1945 2 Sheets-Sheet l oFFgms/wim QZ/ee oFF 0N Jan. 25, 1949.

J. O. LEE

THERMOMETRIC ALARM SWITCH 2 Sheets-Sheet 2 Filed Sept. 6, 1945 PatentedJan. 25, 1949 UNITED nain STAV'IIEZSA PATENT OFFICE THERMMETRIC ALARMSWITCH Jonathan O. Lee, Richmond, Va.

Application September 6, 1945, Serial No. 614,766

1 Claim. l

The instant invention pertains to thermoinetric alarm switches and itsprimary robject is the provision of a switch or circuit breaker which isadapted to close a circuit to sound an alarm when a predetermined'temperature is reached and which is adapted to close a second circuitt'o sound another alarm more audible than the rst alarm when a higherpredetermined temperature `characterist-ic of fire is reached.

Another object of the invention is the provision oi a switch which maybe rendered inoperative before or after the alarm is sounded.

Other objects will appear from the hereinafter description.

The invention consists of certain novel eaturcs of construction,combination and arrange nient of parts, all oi 'which will behereinafter set forth and particularly pointed out in the claim.

In the accompanying drawings which form a part oi this application, Ihave illustrated what I now consider to be the best form o my apparatus.

1n the drawings:

Figure 1 is a front elevation of the preferred embodiment of myinvention;

Figure 2 is a wiring diagram;

Figure 3 is a iront view, partly in vertical section, of thethermo-metric tube and associated parts oi my device;

Figure 4 is an enlarged transverse section taken substantially on aplane as indicated by the line 4 4 of Fig. 3;

Figure 5 is right-hand (Fig. 3) side view or" :i

a portion of the thermo-metric tube;

Figure 6 is a diametral detail section of such tube portion.

In the drawing in which like characters of reference designate like orsimilar parts, numeral 7 indicates a housing of metal, plastic or othersuitable material to house all or parts of the apparatus constitutingthe preferred embodiment of my invention. This housing is provided uponthe upper intermediate portion of its back side with eye lne-ans 3whereby it maf,7 be suspended on the wall oi a room. IThe upper portionVof the front side of the housing has a plurality of slots 4 serving apurpose which will become clear as the description proceeds.

The front wall is also provided with an elonrectangular slot 6 the edgesof which are beveled and which serves as a window for giving theoperator of the device to be described a full or sufficient View of athermo-metric scale 3,

comprising parallel lines indicating a certain temperature of mercury I0enclosed in a glass tube generally indicated by i2. The scale can be soarranged that every line thereon indicates a tem perature five or tendegrees higher or lower than the next lower or higher line. The tubeincludes a spherical bulb i3, a lower tubular section ld of relativelysmall cross section and an upper section i5 of larger cross section.

The cylindrical sections of the tube carry a series of aligned contactsI1, preferably of platinum, each including a pin portion 8 which extendsthrough one of a series of holes in the tube formed on a line of thescale, and also including an enlarged head I9 bearing against the tube.The tube is supported in the housing and behind the window in a suitablemanner. The tube is surrounded above the bulb by the eye portion 2l of aholder 23 and at the top end by a similar eye of a holder. A screw 24lis threaded into the eye and bears with its inner end against the tubeto firmly clamp the same to the holder. The opposite end of eitherholder is formed into an eye 2G. rIhe lower end of a guide rod 23 isinserted in the right-hand (Fig. 3) eye of the lower holder andsupported therein by a flange 29. A similar guide is inserted with itsupper end in the right-hand eye of the upper holder and dependstherefrom in alignment with the lower guide rod. The two adjacent endsof the rods are held in alignment by a sleeve and separated from oneanother by a washer 3i, both of insulating material.

A sleeve 33 is slidably disposed on the lower rod and in electricalcontact therewith and is part of a laterally extending Contact portion35 adapted to contact any of the contacts Il and carrying an angularhandle 36 extending around the lower guide rod and through a slot 3i inthe front wall of the housing. The handle terminates in a hand kncb 38disposed on the outside of the housing. A similar movable contactstructure 33, 35, 35, and 38 is slidable on the upper rod. Each contactportion 35 carries near its free end a semi-circular guide 39 slidableon the thermometric tube (Figs. 3, 4).

Upon the lower portion of the front wall are a pair of switches 43either of which controls a circuit now to be described.

A battery or other source of current 42 is disposed in the housing orelsewhere and has one of its poles connected to one of the switcheswhich is also connected to a buzzer 44. The same is connected by aconductor 45 to a xed conducting sleeve 46 on the lower guide rod. A pin41 extends through the wall of the bulb into the mercury and isconnected on the outside by a conductor 43 to the other side of thebattery.

One side of a second battery 59 is connected to the other 49 of the twoswitches which is also connected to an electric bell 52. The other sideof the same is connected by a conductor 53 to a sleeve 5d on the lowerend portion of the upper guide rod. A second pin lll' extends into thebulb and is connected on the outside by a conductor 55 to the other poleof the battery 59.

In order to operate the device the lower handle knob is manipulated sothat its contact portion-l contacts the head of one of the pins having ascale number of the temperature which is to be announced. The upper handknob is manipulated to set its contact on the head of the pin having ascale number of the fire temperature. The two switches are closed.

When the mercury in its expansion reachesrthe lower temperature forwhich the lower indicator has been set a circuit is completed. In thiscircuit the mercury bridges the left-hand bulb contact and the lowertube contact 35 and the buzzer is operated.

When the mercury reaches the upper scale number and xed contactassociated therewith on which the upper movable contact 95 is set, acircuit is closed which includes the upper fixed Contact and the bulbcontact to the right and sounds the bell indicating that the mercury hasreached the scale number for re temperature. The slots 4 render thesound of the buzzer and `bell more audible.

VWhile I have shown and described the preferred embodiment of myinvention it is of course to be understood that I reserve the right tomake such changes in the form, construction and arrangement of parts aswillv not depart from the spirit of the invention or the scope of thesubjoined claim.

What I claim and desire to protect by Letters Patent is:

In a device of the class described, an expansible liquid thermo-meterincluding a bulb having a tube communicating therewith and risingtherefrom, a series of longitudinally spaced terminal pins projectingthrough the wall of the tube of the thermo -meter above the bulb thereofand having contact heads exterior to the tube, a guide of electricalconducting material extending parallel to the tube, a movable electriccontact slidably disposed on the guide and having a portion forselective engagement with the heads of the terminal pins, an arcuateguide element carried by the movable contact having portions disposedfor engagement with the tube on either side of the heads of the terminalpins for maintaining said Ymovable contact portion in position to engagethe terminal pin head disposed on the same plane as the movable contact,and a conductor pin extending through the Wall of the bulb and inconstant Contact with the expansible liquid for completing an electricconnection therefrom to the rst mentioned guide through the liquid andthe terminal pin engaged by the liquid and movable contact.

JONATHAN O. LEE.

REFERENCES CITED The following references are of record in the file ol'this patent:

UNITED STATES PATENTS Number Name Date 338,090 Loomis Mar. 16, 1836409,996 Meyer Aug. 27, 1889 478,701 Maxim et al July l2, 1892 783,141Schick Feb. 2l, i905 935,460 Carpenter Sept. 28, 1909 1,600,896 LeinesSept. 21, i926 FOREIGN PATENTS Number Country Date 13,647 Great Britain1895 529,571 France July 25, 1922

